Key pulsing b operator position circuit



Sept. 18, 1951 H. E. NowEcK ETAL I 2,568,164 Y KEY PULSING B OPERATOR POSITION CIRCUIT Filed June 29, 1948 4 Sheets-Sheet 1 W/TO T. o. Ro@

@Y @am A T7' ORNE V Sept' 18, 1951 H. E; NowcK ETAI.l 2,568,164

KEY Pun-SING B OPERATOR PosTIoN cIRcuiT Filed June 29. 194s:

4 Sheets-Sheet 2 By ma@ A T7' ORNE V Sept- 18, 1951 H. E. Nowl-:CK ETAL KEY PULSING B OPERATOR POSITION CIRCUIT 4 Sheets-.Sheet 5 Filed June 29, 1948 H. E. NOWECK /NVENTORS 7:0. ROBE ATTORNFV Sepi- 13, 1951 H. E. NowEK ET AL KEY PULSING B OPERATOR POSITION CIRCUIT Y 4 Sheets-Sheet 4 Filed Jlne 29, 1948 '/M/ENTORSH E NOWECK BV zo. R053 A T TOR/VE Y Patented Sept. 18:2 1951 KEY PULSING B OPERATOR POSITION CIRCUIT Herman E. Nowcck, Mountain Lakes, and Theodore D. Robb, Ridgewood, N. J., assignors to Bell Telephone Laboratories, Incorporated, New York, N. Y., a corporation of `New York Application June 29, 1948, Serial No. 35,846

3 Claims.

This invention relates to telephone systems and particularly to systems comprising operator positions for completing calls to both manual and automatic oices.

Objects of the invention are the provision of improved operator position equipment for use in extending calls incoming from other .operator positions to both manual and automatic oiiices and an increase in the efliciency in the handling of such calls.

This invention is an improvement in B operator position equipment which is arranged for automatic individual connection to straightforward trunks incoming from another operator po- Sition, for automatically transmitting an order tone signal over the connected incoming trunk `to indicate that the operator is waiting to re- Vfying the digits of the called subscribers number, and a key the operation of which effects the association of the key set with the incoming trunk and also the transmission of another and different order tone signal over the incoming trunk to indicate that the operator is waiting to receive the called subscribers number. A-feature of the invention is the provision of means in the incoming trunk circuit for disconnecting the operators telephone set and position equipment immediately upon extension of the con 'nection to an outgoing trunk for completion by the straightforward method of operation and the provision of means for maintaining the connection between the incoming trunk and B operator equipment after connection of the incoming trunk to an outgoing key pulsing trunk until the transmission of digit signals has been completed.

The drawing shows schematically a telephone system comprising trunk and operator position equipment arranged in accordance with this invention. Referring to the drawing:

Fig. 1 shows a calling subscribers station X and line LI in a local oiiice and a trunk I between the local office and a toll oiiice; and shows in the toll oiiice, an incoming trunk circuit Il, an A operators cord CD, position circuit OP and telephone set, and a switching trunk Tl which manual oice.

is jack-ended at the A operator position and which is plug-ended at a B operator position;

Fig. 2 shows the B operators telephone and grouping key circuits and a position release circuit. Fig. 2 further shows one of a group of jackended trunk circuits each associated with a trunk outgoing to a manual local oice and one of a group of jack-ended trunk circuits each associated with a trunk outgoing to a local dial oilice. Fig. 2 further shows in a step-by-step local dial office, an incoming trunk circuit, an incoming selector, a connector, and a called subscribers line L2 and station Y;

Fig. 3 shows the B operators key set circuit;

Fig. 4 shows the B operators order tone circuit; and

Fig. 5 shows the relative position' in which Figs. l to 4 are to be placed to form an operative arrangement.

The local olice serving the calling station X may be either a manual or dial oice of known type arranged to complete local calls and to connect calling lines to trunks terminating at A operator positions. of a toll office. The toll A operator cord, position and telephone circuits may be similar to those disclosed in Patent 1,675,956 granted July 3, 1928 to L. F. Porter.

The trunk circuit Tl, which is a three-conductor trunk jack-ended at A operator positions of the toll board and plug-ended at a switching or B position of the same toll board, is shown in detail; and so also are the order tone, key set and position release circuits. The trunk circuit Tl and B operator position are arranged for automatic listening, call sequence relays being provided for connecting calling incoming trunks such as TI to the operators telephone and order tone circuits, one trunk at a time. Reference may be had to Patent 1,632,051 granted to W. Whitney, June 14, 1927 for further disclosure of a B operators position and trunks arranged for automaticY listening and ord-er vtone transmission. Reference may also be had to Patent 1,767,929 granted to I-I, B. Johnson,v June 24, 1930 for disclosure of an arrangement for vgrouping a plurality of operators positions under control of one operator.

The trunk associated with outgoing trunk circuit 56 is used as a straightforward trunk and terminates at a B operator position in a' local Reference may be had to Patent 1,751,207 granted March 18, 1930 to H. B. Johnson for disclosure of a toll switching trunk terminating in a manual localoice for straightforward operation.

The trunk circuit 52, link circuit 53 and key pulsing sender circuit 54 are of known type and may be similar to the trunk, link and sender circuits disclosed in Patent 1,916,760 granted July 4, 1933 to I. H. Henry. The associated trunk T2 terminates in incoming trunk circuit l in a step-by-step local oice which comprises incoming selector and connector switches 58 and 59 for completing connection with a called line under the control of the sender 54 in the manner set forth in said patent to I. H. Henry.

Assume now that a call has been initiated at a subscriber-s station X in a local office, and that the subscribers line LI is connected in the local oihce to an outgoing trunk terminating in incoming trunk circuit I I in a toll Oliice, that the incoming trunk circuit is jack-ended at a toll board, and an operator yat the toll board an- 4 With relays 26 and 22 operated, a circuit is closed from battery through the right front contact of relay 26, a back contact of relay 24, a back contact of relay 25, inner upper front contact of relay 22, conductor .39, back contact of relay I I6 of .the order tone circuit, a back contact of relay .y |05, winding of-relay I I, conductor H0, through circuit for operating relay H3; relay H3 closes a circuit for operating relay H4; relay I I4 closes a circuit for operating relay H5; relay I |5 closes a circuit for operating relay H6; relay H6 opens the operating circuit of relay III and closes a swers the call by connecting the plug I3 of a direct access to trunks terminating in the called oce, the call may be completed by connecting the plug I4 to the jack I5 of an idle one of these trunks. If, however, the answering toll operator does not have direct access to the called ofiice, the .plug I4 is connected to the jack I6 of an oilice switching trunk TI which terminates at a B operator position of the toll board, at which position the plug-ended switching trunk TI may be connected to -another switching trunk that terminates in the called-office.

When plug I4 is inserted in jack I6, a circuit is closed, through the sleeve 4conductors of the plug and jack, for energizing the right winding of sleeve relay of the associated trunk circuit TI. The operation of relay 20 closes a circuit for operating relay 26. The operation of relay 26 lights the trunk lamp LI; closes a connection from groundthrough its left outer front contact, a back contact of relay 25, and aback contact jof relay 24, to 'one end of the winding vof the call vsequence relay 3|; and connects the tip of the plug PI of trunk circuit TI to the busy test conductor 4i) leading to the operators telephone circuit 60. As soon thereafter as the 'call sequence relays (which are yshownronly in part) are in condition for connecting trunk circuit Tl to the loperator telephone circiut 60, battery is connected i-n the operator position circuit through conductor 38 tothe other side of the winding of sequence relay 3|, thereby effecting the operation `of relays 3l and 32 in succession. The 'operation of relay 32 connects the Winding ofrelay 212 yof trunk circuit TI in series with the winding -o'f "the common ysequence relay 33, both of relays 22 and `3'3 being thereby operatively energized. The operation of relay 22 closes a 'circuit for operating relay 23 and closes a connection between the answering fopera'tors telephone and the B Olperators order tone circuit; which connection includes the tip 'and ring conductors of plug I4 and jack |16, front contacts of relay -22 of trunk circuit TI, conductors 43 and 44, backcontacts of relay |05 of the o'rde'r tone circuit, and one winding 'of induction coil |06 in series with condenser |0'|` Relay 33 Yconnects the winding vof relay 35 to interrupter 34 to alternately operate and release relay 35; and, with relay 22 operated, the trunk lamp lll is flashed under the control -of vrelay 35, indicating that 'trunk circuit TI iS associated with the operators telephone .60.

circuit for operating relay |05. Each of relays ||"2,"|I3, I'Ill1 H5 and H6 is a slow-to-release relay; "a'nd, during the operation of these relays in succession, the high tone source H1 is connected to the right winding vof induction coil |06 to transmit three impulses of tone through the above-traced connection between the left winding of coil |06 and the A operator. The first pulse begins when relay III operates and ends when relay H2 operates; the second pulse begins when relay H3 operates and ends when relay H4 operates; and the third pulseL begins when relay H5 operates and ends when relay |05 operates. The B operator also hears the tone impulses since conductors 43 and 44 are at this time connected through condensers |03 and |04 -and conductors ISII and |02 to the B operators I inner right :ba'ck Contact of relay |25 and 'conductor V39, to battery in trunk circuit TI as hereinbefore traced.

If the call is one to be completed over an outgoing straightforward trunk to another Inanual oflice, the B operator 'inserts .plug Pl in Va jack 55 associated with voutgoing trunk circuit 56. The windings of relays 29 and 30 in series are thereby connected through the sleeve conductors of plug P'I and jack .55 to the sleeve conductor of the outgoing trunk circuit 56 in which this conductor is connected through the high resistance winding Iof :a sleeve relay to ground and fis also connected through the low vresistance winding of the sleeve relayto ground under the control of vthe answering supervisory relay, neither the sleeve -nor thelanswering supervisory .relays of trunk circuit 56 being shown. Relay 29 operates but relay 30 is marginal and does not operate until the low resistance windconductors of plug PI to the tip and ring conductors of jack I6. I'he disconnection of ground from conductor 31 causes the release of call sequence relays 3| and 32 and thereby eiects release of relay 22 of trunkcircuit TI. The release of relay 22 effects the release of relay 23, the operation of relay 23 being without useful function on a call which is not completed over a trunk arranged for key pulsing. With relay 22 normal, the talking conductors of jack I6 are connected through the tip and ring conductors of plug PI and jack 55 to trunk circuit 56. The A operator receives order tone fromv the called manual office, in the manner described in the aforementioned patents to WA Whitney and B. Johnson, and passes the called number to an operator in the called oilic'e, who thereupon completes the connection to the called line. When the call is answered, the connection of ground to the aforementiond low resistance winding of the sleeve relay of trunk circuit 56 causes the operation of relay of trunk circuit TI. The operation of relay 30 connects ground to the low resistance winding of relay 28 thereby lighting the supervisory lamp I1 associated with plug I4. When relay 3|] releases due to disconnection of ground from the low resistance winding of the sleeve relay of trunk circuit 58, ground is likewise disconnected from the low resistance winding of relay 28 thereby extinguishing lamp I1.

When the A operator disconnects plug I4 from jack I6, relays28 and 26 release in succession. With relay 28 operated, the release of relay 26 closes a circuit for operating relay 21; and relay 21 locks independent of relay 26 so that insertion -of a plug in jack IB is ineffective to release relay 21 as long as relay 28 remains operated. The

operation of relay 21 causes the release of relay 24, lights the trunk lamp LI as a disconnect signal, and prevents the transmission of a supervisory signal to any cord which may be connected to jack I6 before plug PI is disconnected vfrom jack 55. The release of relay 24 opens the talking connection between jack I6 and trunk circuit 56. If a plug is againconnected to jack I6 before plug PI is disconnected from jack 55, relays 28 and 26 are operated and the trunk circuit TI is connected to the B operators telephone circuit as hereinbefore described; but it is necessary for the plug PI to be disconnected from jack 55 in every case to enable the extension of another call. When plug PI is removed from jack 55, relays 29, 30 and 21 release; and, with no plug in jack I 8, the lamp LI is extinguished. In case the plug PI is disconnected 'over a trunk arranged for key pulsing. The B operator thereupon momentarily operates the KP key of the position key set circuit and then inserts plug PI in a jack 5| associated with a trunk circuit 52. closes a circuit for operating relay 11; and relay 11 locks independent of the key. The operation `of relay 11 closes a circuit for operating relay 18, opens the connection between conductors |3I The operation of the KP key, 70

vand |32 of the order tone circuit, connects groundclo of relays II3 and II4.

to conductors |32 and |33, disconnects ground from conductor |34, opens the connection ben tween conductor 15 of the position release circuit and conductor 64 of the grouping key circuit and connects conductor 15 to the winding of relay 95 of the key set circuit. The operation of relay 18 lights lamp 19 to indicate that the key set circuit is associated with the trunkV circuit: closes a circuit through resistor 88 for 'energizing the lower biasing Winding of relay 91;'connects ground to conductor 61, thence through the grouping key circuit, conductor 41, a front contact of relay 23 and conductor 4I to operate relay |25 of the order tone circuit; connects resistor 8| in parallel with the winding of relay 82; connects ground to conductor 42 to hold relay 23 of trunk circuit TI operated; connects ground to conductor 68, thence through the grouping key circuit, conductor 48, a front contact of relay 23 and conductor 31 to hold the call sequence relay 3| operated; and connects ground to conductor The insertion of plug PI in jack 5| causes the operation of relays 29, 28 and 24, relay 3| being held operated, after relay 24 operates, under the control of relay 18 of the key set circuit. The trunk circuit 52 thereupon functions to eiect the operation of a link circuit 53 to associate an idle sender 54 with trunk circuit 52. Refer--l ence may be had to Patent 1,916,760'granted July 4, 1933 to I. H. Henry for a complete description of the operation of trunk, link and sender circuits arranged for cooperation with an operators key set circuit. When an idle sender 54 is attached to trunk circuit 52, a relay in the sender is operated, as described in the aforementioned Henry patent, in a circuit from battery at the right back contact of relay 95 of the key set circuit, through resistor 96, a back contact of relay 92, a front contact of relay 18, conductor 66, through the grouping keycircuit. conductor 46, front contacts of relays 23 and 24. ring conductors of plug PI and jack 5|, through the key pulsing ring conductor of the trunk and link circuits 52 and 53 to the sender circuit 54. In the sender, battery is now connected to the key pulsing tip conductor thence through the link and trunk circuits 53 and 52, tip conductors of jack 5| and plug PI, front contactsfof relays 24 and 23, conductor 45, through the grouping key circuit, conductor 65, continuity contact and winding of relay 9I, to ground at a front contact of relay 18. Relay 9| operates,'closes a locking circuit under the sole control of relays 18 and 95, and closes a circuit which includes back contacts of relays 95 and 98 for operating relay 92. The operation of relay 92 extends the tip and ring key pulsing conductors and 66 toconductors 89 and 90 of the numerical'key set;' connects battery through resistance lamp 93 to conductor 89; connects battery at the right back Contact of relay to the upper and middle windings of relay 91, connects conductor 89 to the other end of the upper winding of relay 91, and lights the sender-attached-signal lamp 94 to indicate that keying of the called number may be started.

The above-mentioned operation of relay |25 of the order tone circuit closes a circuit for operating relay |26; opens the holding circuit of relay |05, thereby effecting the release of relay |05; and rearranges the sequence of operation of the order tone relays so as to skip the operation The release of relay |95 recloses the Vcircuit for operating relay ||I. A

rst impulse of tone is thereupon started when relay operates and ended when relay ||2 operates; .and a second impulse is started when relay ||5 operates and ended when relay H0 operates. Relay ||6 again closes the circuit for operating relay |05 and relay |05 locks under the control of relay |26. Responsive to the two tone impulses, the A operator passes the called station number to the B operator, and as soon as the sender-attached lamp S is lighted the B operator depresses the corresponding keys of the numerical key set, one at a time. The key set impulses thereby transmitted to the sender 54 effect the registration of the called number. The start key ST is operated after the last numerical key has been depressed, thereby op erating relay 82 to transmit impulses to indicate that keying has been completed. During the transmission of digit impulses, the upper and middle windings of relay 91 are energized but relay 91 does not operate due to the energization of its biasing winding. When all the digits have been registered in the sender, battery of a higher voltage is connected in the sender to both of the key pulsing conductors so as to effect the operation of relay 91. Relay 31 closes a circuit for operating relay 98. Relay 98 locks under the control of rela-y 18closes a short circuit across Athe biasing winding of relay 91, so that relay 91 will be held operated by only one of its operating windings, and then disconnects battery from and connects ground to the key pulsing ring conductor 06 as a start ringing signal to the sende-r. The sender thereupon disconnects battery from both of the key pulsing conductors, releasing relay 91. The release of relay 91 connects ground through its left contact, a front Contact of relay 33, a front contact of relay 92 to resistor 16; thereby short circuiting and causing the release of relay 11. The release of relay 11 effects the release of relays 18. 9|, 92 and 93 thereby restoring the key set circuit to normal, including the disconnection of ground from conductors 42, .61, E8 and |33 and the reconnection of ground to conductor |34. The disconnection of ground from conductor 31 effects the release of relays |25 and |26 of the order tone circuit. The disconnection of ground from conductor 42 opens :the locking vcircuit of relay 23; and the disconnection of ground from conductor 68 causes the release of call sequence relays 3| and 32 followed by the release of relays v22, 33 and 23.

In case of necessity, for instance if the call sequence relays fail to operate, the B operator may connect plug Pl to the emergency listening jack |30 of the order tone circuit whereupon relay 2S of the trunk circuit and relay |20 of the order tone circuit are operated in series. Being Vmarginal, relay 30 does not operate in series with relay |29. The operation of relay 29 causes the operation of relays 28 and 24 in succession; `and the, operation or relay |20 closes -a circuit for operating relay 12| and connects :battery directly to conductor 39 to cause the order tone circuit to operate as -hereinbefore described. After receiving the oiiice code, the plug PI is removed of its lower Winding in a circuit which includes the back contact of relay 28, ring conductor of plug P| and jack |30, a front contact of relay l2 conductor |32 and a front contact of relay 11.

It it is found that call cannot be com-pleted after it has been extended to a switching trunk TI and this trunk has been connected to the lB operator telephone set `(i0, the B operator may release the trunk circuit T| by operation of the position release key 10. The operation of key 10, which must be maintained until release has been effected, causes the operation of relay 1|. Relay 1| disconnects ground from conductor I0 to release relay of the order tone circuit, if operated. If the KP key has not been operated relay 1| closes a circuit for operating relay 14 of the position release circuit and relay 25 of the trunk circuit TI in series. This circuit is traced from ground at the front contact of relay 1|, through the back contact of relay 1 2, Winding of relay 14, conductor 15, back contact of relay 11, `conductor 5, through the grouping key circuit, conductor 49, a front .contact of relay 23 of trunk circuit TI continuity contact and winding of relay 25, a back contact of relay 24, and through a front contact of relay 2G to battery. Relay 1li closes a circuit for operating relay ,1.3. Relay 25 locks to ground at its front Contact, disconnects `battery from conductor 39, and disconnects ground from conductor 31 thereby causing the release of the call sequence relays 3| and 32 in succession. The release of relay 32 causes ythe release of relays 22 and 23 thereby terminating lthe hashing of lamp LI and closing a circuit for lighting lamp LI steadily. When relay 25 operates, relay 14 releases due to thc opening of the series .circuit through the Windings 0f these relays. When relay 111 releases, relay 13 is held operated and relay 12 operates in a series circuit, which circuit is maintained .until relay 1| releases upon release of key 1,0.

If lan error is made in keying the called ,number and discovered before the key setl circuit is -released by the sender, the vkey set is released by removing the plug PI from the key pulsing trunk Jack vand then operating the position release key 10. 41n this case the operation of relay l1| closes a circuit through the Awinding of relay 14, conductor :15, a front contact of relay 11 vand the winding of relay in the key set circuit. The operation of relay 05 causes the successive release of ,relays 9| and 92, but relays 11 and 1,8 remain operated. When relay 1| releases, relay i2 operates in .series with the windings of relays 95 and y13. The operation of relay 12 causes its own .release andthe release of relay 14 followed by the release ofrelay 13. The B operator may now plug into a key pulsing trunk jack and keying may start when the sender attached signal zlights as hereinbefore described.

What is claimed is:

1. In a telephone system, an operator ,position comprising a telephone set and a key pulsing key set lfor transmitting digit signals, incoming trunks vterminating at said position, outgoing trunks arranged -for straightforward operation. outgoing trunks arranged lfor key pulsing, means for automatically connecting said incoming trunks 4one at a-time -to said -position telephone set, lmeans responsive to the connection of an key for connecting said key set with said incoming trunk, relay means operated upon connection of said key set to said incoming trunk for transmitting over said incoming trunk a different plurality of order tone impulses, means for disconnecting said incoming trunk from said telephone set as soon as said incoming trunk is connected to an outgoing trunk arranged for straightforward operation, relay means rendered effective by the operation of said key for maintaining the connection of an incoming trunk to said telephone set after said incoming trunk is connected to an outgoing trunk circuit arranged for key pulsing, means comprising said key set for transmitting digit signals over an outgoing key pulsing trunk to which said incoming trunk is connected, and means effective after the transmission of said digit signals to disconnect said telephone set and key set from said incoming trunk.

2-. In a telephone system an operator position comprising a telephone set and a key set, one key for each different signal to be transmitted, incoming trunks terminating at said position, outgoing trunks arranged for key pulsing, means for connecting a calling incoming trunk to said telephone set, means responsive to the connection of an incoming trunk to said telephone set for transmitting a tone signal over said incoming trunk, means comprising a key for connecting said key set with said incoming trunk, and means effective responsive to the association of said key set with said incoming trunk for transmitting a different tone signal over said incoming trunk.

3. In a telephone system an operator position comprising a telephone set and a key set, one key for each different signal to be transmitted. incoming trunks terminating at said position, outgoing trunks arranged for key pulsing, means for connecting a calling incoming trunk to said telephone set, means responsive to the connection of an incoming trunk to said telephone set for transmitting a tone signal over said incoming trunk, means comprising a key for connecting said key set with said incoming trunk, means effective responsive to the association of said key set With said incoming trunk for transmitting a diierent tone signal over said incoming trunk, manual means for connecting said incoming trunk to an idle one of said outgoing trunks, and means for maintaining the operative association of said incoming trunk and key set while said key set is being operated to transmit signals over said outgoing trunk.

HERMAN E. NOWECK. THEODORE D. ROBB.

REFERENCES CITED The following references are of record in the iile of this patent:

UNITED STATES PATENTS Number Name Date 1,795,813 Whitney Mar. 10, 1931 1,916,760 Henry July 4, 1933 2,259,100 Dahl Oct. 14, 1941 2,332,885 Bakker Oct. 26, 1943 

